Automatic ice maker water line with meniscus control

ABSTRACT

A water supply conduit extending through the insulation of a refrigerator top wall with its outlet nozzle positioned above the freezing tray of an ice maker. The conduit has its intermediate generally horizontally disposed portion formed with a reduced tubular throat such that the receding movement of the meniscus of the liquid in the conduit stops at the downstream side of the throat when the water line flow is shut off by valve means, to control the positioning of the water change and thereby prevent water drippage from the conduit outlet to obviate ice blockage of the line.

United States Patent [191 Kochendorfer et al.

[ AUTOMATIC ICE MAKER WATER LINE WITH MENISCUS CONTROL [75] Inventors: Donald P. Kochendorfer; Charles C.

Whistler, Jr., both of Dayton, Ohio [73] Assignee: General Motors Corporation,

Detroit, Mich.

[22] Filed: Sept. 20, 1973 [21] Appl. No.: 398,932

[56] References Cited UNITED STATES PATENTS l2/l947 Caesar 62/345 X 11/1961 Linstromberg et al. 62/340 [451 Sept. 17,1974

3/l962 ll/l970 Janquart 62/353 X Eyman et al 62/353 X 5 7 ABSTRACT A water supply conduit extending through the insulation of a refrigerator top wall with its outlet nozzle positioned above the freezing tray of an ice maker. The conduit has its intermediate generally horizontally disposed portion formed with a reduced tubular throat such that the receding movement of the meniscus of the liquid in the conduit stops at the downstream side of the'throat when the water line flow is shut off by valve means, to control the positioning of the water change and thereby prevent water drippage from the conduit outlet to obviate ice blockage of the line.

' 3 Claims, 5 Drawing Figures AUTOMATIC ICE MAKER WATER LINE WITH MENISCUS CONTROL This invention relates to liquid dispensers for refrigerators and more particularly to a water line leading to the freezing tray of an automatic ice maker through the top wall of the cabinet into the freezer compartment of a household refrigerator.

It has been determined that in the design of water supply lines provided in household refrigerator cabinets that it is desirable to maintain a low water velocity to minimize turbulence and splash as the water flows into the freezing tray of an automatic or semiautomatic ice maker. If the water supply line is horizontally disposed within the top wall of the cabinet for location in a limited space above the freezer compartment, however, it is not always possible to provide exact orientation during assembly so as to consistently maintain complete drainage of the supply line after each fill cycle of the ice maker without locating a portion of the water line in the cabinet wall potentially subjected to below freezing temperatures. Thus, unless the refrigerator cabinet top wall is maintained in an exact horizontal position, a slope will be imparted to the water line. Depending upon the particular slope of the water line with respect to the horizontal, the meniscus of the water charge within the line may be located at various portions therein. If the meniscus is allowed to vary over an extended range during the tray fill cycles, residual water will accumulate in the line because of the wetting thereof resulting in a slow drippage of water at the outlet orifice of the water line within the freezer compartment which will build up an ice barrier by freezing the water in layers causing an eventual blockage of the line.

The present invention has as its primary object the provision of an improved water supply conduit for assisting in the rapid shut-off of water flowing to the freezing tray or mold of a refrigerator ice maker to pre vent a slow drippage of water after the fill cycle, causing an accumulation of ice and blockage of the conduit.

Another object of the invention is to provide a meniscus control for a water supply line which extends through the insulated top wall of a refrigerator cabinet having an outlet orifice positioned above the freezing tray of an automatic ice maker in which an intermediate generally horizontally disposed portion of the water line is fonned with a reduced tubular throat designed such that the movement of the meniscus of the water charge in the conduit at flow shut-off stops at the downstream side of the throat to prevent further exiting of the water from the outlet when the water flow is interrupted by valve means located in the water supply line.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the invention is clearly shown.

IN THE DRAWINGS FIG. 1 is an irregular sectional view of the refrigerator embodying an automatic ice maker illustrating one form of the invention;

FIG. 2 is an enlarged fragmentary side elevational view, partly in section, of the ice maker water inlet tube;

FIG. 3 is an enlarged top elevational view of the water line with parts broken away;

FIG. 4 is a sectional view taken on line 4-4 of FIG.

FIG. 5 is a section taken on the line 5-5 of FIG. 2.

Referring to the drawings and more particularly to FIG. 1, there is shown a frost-free type household refrigerator 20 with an upper below freezing compartment 22 closed by insulated door 24 and a lower above freezing compartment 26 closed by lower insulated door, the top edge of which is shown at 28. These compartments are surrounded by insulated cabinet walls, only the top 29 and rear 30 walls of which are shown, and separated by horizontal insulation wall 32 containing an evaporator compartment 34 provided with a finned evaporator 36 having vertical fins extending from the front to the rear of the compartment 34.

The evaporator compartment is provided with an inlet 38 at the front communicating with the front of the below freezing compartment 22 and additional inlets (not shown) communicating with the top of the above freezing compartment 26. At the rear, the compartment 34 connects with a shroud 40 communicating with the entrance to a centrifugal fan 42 which is driven by electric motor 44 housed in the rear wall 30 of the cavity. The cooling arrangement for the compartments may be similar to that shown in US. Pat. Nos. 3,359,750 or 3,310,957 which may be referred to for further details of the construction of the refrigerator.

The fan 42 is provided with an upwardly extending discharge duct 46 having a distributor 48 in the top which distributes the discharge of air through the below freezing compartment 22. The evaporator 36 is maintained in a suitable below freezing temperature such as 5 to -l5 F. to maintain the compartment 22 at the temperature of 0 F. or below.

For providing special cooling for the automatic freezer, the distributor 48 is provided with a laterally extending discharge duct 50 extending along the intersection of the rear 30, and top 29 walls. Behind the automatic ice maker or liquid freezer 52 the lateral extending duct 50 is provided with wide discharge nozzle 54 which discharges the cold air directly onto the top of the liquid freezer 52 and particularly onto the top of the freezing tray or mold 56.

The mold 56 is provided with two rows of pockets 58 containing four compartments in each row. It is to be understood, however, that the particular configuration of the mold pockets is not important to the present invention and any conventional mold configuration could be used in the automatic ice maker 52. The mold 56 is supplied with the water or any other liquid to be frozen from a pressure water system to a solenoid control valve 62 which controls the flow of water through a filler or water supply conduit or line 64 extending through the insulation of the top wall 29 to position a discharge nozzle or outlet 65 below the inner liner 67 of the below freezing compartment 22 above the front pockets 58 of the mold 56.

The details of the automatic ice maker 52 disclosed in the present invention are shownin US. Pat. No. 3,540,227 issued Nov. 27, 1970, to C. W. Eyman, Jr. et aL-and assigned to the same assignee as the present invention and reference is made to that patent for more complete description of the ice maker and its mode of operation.

Referring now particularly to FIGS. 2 and 3, the water supply conduit generally indicated at 64, which preferably is formed by blow molding from a suitable plastic material such as polyethylene, will be described in detail. As best seen in FIG. 1, the inlet portion 66 of the conduit is formed in a smooth curve and extends through an opening 70 in the outer metal shell 72 of the rear wall 30. The opening 70 comprises a resilient grommet 74 that is adapted to be fastened therein allowing the rearwardly projecting horizontal leg portion 76 to extend in a sealed manner through the grommet opening positioning the downwardly directed coupling spout 78 exteriorly of the cabinet. A suitable fitting on cold water line 80 is adapted to engage the coupling spout 78 in liquid-tight relationship.

The smooth arcuate portion 66 of the conduit 64 blends into a generally horizontal upstream tube 81a and downstream tube 81b which in the preferred form of the invention is shown nested in the channel portion 82 of the U-shaped insulation block member 8 3 formed from suitable material such as rigid polyurethane foam. It will be noted in FIG. 4 that the horizontal upstream and downstream tubes 81a and 81b, respectively, separated by reduced tubular neck 86 are formed with planar flat upper surfaces 88a and 88b which are positioned substantially flush with the upper surface 89 of the insulation block member 83. As seen in FIG. 1 by virtue of the tubes 81a and 81b being formed with the flat upper surfaces 88a and 8812 the conduit 64 can be located with the surfaces 88a, 88b adjacent to the inner surface of the cabinet top wall outer metal shell 90 to provide a maximum heat conducting path for conducting heat from the ambient air exterior to the cabinet to the conduit 64 to prevent freezing of the water therein.

The water supply or filler conduit 64 has its discharge nozzle 65 positioned above the tray 56 of the ice maker. The solenoid valve 62 in the water supply line 80 connects the conduit 64 to a suitable source of water, as for example, to the house water supply in such a manner that when the solenoid valve is energized to open the valve, water flows through the supply line 80 into the conduit 64 and discharges into the tray 56 via the nozzle 65. Automatic control of the water supply means is obtained bymeans of control valve circuitry essentially including a switch (not shown) adapted to complete a control circuit for the valve which opens the valve when the tray 56 is in its upper position after the completion of an ice harvest cycle. Details of one such control circuit are disclosed in the abovementioned US. Pat. No. 3,540,227.

As best seen in FIG. 2, the water conduit tubes 81a and 81b form the relatively long, generally horizontal upstream and downstream passages 84a and 8412 respectively, positioned on either side of the intermediate reduced tubular neck portion 86. The downstream passage 84b is formed with a smooth downwardly curved forward portion 92 terminating in an outlet end or nozzle 65, received in angularly positioned bushing 94 of molded plastic insert 96, which insert is adapted to be located in an opening 98 in the inner liner 67 of the top wall 29. It will be noted that the molding insert 96 also includes an angled bushing 102 for receiving the inner end 103 of an electrical conduit 104, formed from a suitable plastic material, positioned substantially parallel with the water supply conduit 64 with its outer end 106 extending through a second opening in the grommet 74. The electrical conduit 104 provides a passageway for electrical wiring 108 leading to the power and control terminals of the ice maker control panel M0.

The horizontal passages a and b of the water supply conduit 64 have intermediate reduced tubular neck portion 86 formed approximately midway between the front 92 and rear 66 downwardly curved portions of the conduit. As best shown in FIG. 4, the principal axis of throat passage 112 formed by neck 86 is coincident with the principal axis of the conduit passages 84a, 84b and has a radius of the order of one-half the radius of the lower arcuate portion of the passages 84a, 84b. Thus, as seen in FIG. 4, both the upstream and downstream portions of the generally horizontal intermediate passages of the water supply conduit 64 have composite cross sections which are symmetrical about a vertical plane coincident with the conduit principal axis and extending longitudinally thereof. Said differently, the upper half of the passages 84a, 841; have a semi-square cross section and the lower half have a cylindrical cross section encompassing about 180 in arcuate extent.

As stated earlier the composite configuration of the passageways 84a, 841) provides the flat upper surfaces 88a, 88b which are positioned adjacent the inner surface of the outer top wall of the refrigerator cabinet so as to provide a good heat conducting path for conducting the heat from the air exterior of the cabinet to the water supply conduit thereby preventing any freezing of the supply water charge while it is stored therein.

To insure the provision of a heat conductive path between the water supply conduit 64 and the outer shell 90 of the cabinet, the conduit 64 is assembled with a suitable elastic sealing compound deposited longitudinally along the upper flat surfaces 88a, 88b such that when assembled the elastic compound will be cornpressed into a layer indicated at 113 between the flat surfaces 88a and 88b and the inner surface of the shell 90 to prevent the entry of any insulating materials therebetween during the foaming operation of the insulation.

As viewed in FIG. 2, the throat 112 has frusto-conical surfaces 114 and 116 on both its upstream and downstream sides respectively, with the bases thereof forming connections with their associated passages 84a and 84b to provide smooth transition for flow of the water both on its entrance and exit from the throat H12.

While the embodiment of the present invention constitutes a preferred form, it is to be understood that other forms might be adopted.

We claim:

I. A supply conduit for positioning between the inner liner and the outer shell of a refrigerator cabinet insulated top wall for supplying water to a freezing tray of an automatic ice maker, said conduit comprising; an intermediate linear portion formed with downwardly extending inlet and outlet portions, respectively, at each end thereof; said linear portion having a flattened upper surface for positioning in juxtaposed relation with the refrigerator top wall outer shell, said conduit intermediate portion having a reduced cylindrical tubular portion interposed between upstream and downstream segments of said linear portion, said reduced tubular portion having frustoconicai sections on both its upstream and downstream ends joining with said upstream and downstream linear segments, respectively; whereby upon said conduit supplying a predetermined charge of water to the tray the flow of water to said conduit is stopped and the meniscus of the water remaining in said conduit is retained adjacent the downstream end of said tubular portion obviating blockage of said supply conduit by preventing water drops from exiting and freezing at said conduit outlet portion.

2. A supply conduit for positioning between the inner liner and outer shell of a refrigerator top wall for supplying water to a tray of an automatic ice maker comprising, an intermediate linear portion formed with smooth downwardly curved inlet and outlet portions respectively, at each end thereof; said conduit intermediate portion having a flattened upper surface so as to be in juxtaposed relation with the refrigerator top wall outer shell, said conduit intermediate portion having a composite cross section whereby the upper half thereof forms a semi-square and the lower half forms one-half of the cylinder, said conduit intermediate portion having a reduced cylindrical tube positioned about midway between said inlet and outlet downwardly curved portions, said reduced tube being concentrically aligned with said lower cylindrical portion and having a radius of about one half thereof, said tube having frustoconical sections on both its upstream and downstream ends joining with said conduit intermediate portion, whereby upon said conduit supplying a predetermined charge of water to the tray the flow of water through said conduit is stopped and the meniscus of the water remaining in said conduit is retained adjacent the downstream end of said tube to obviate blockage of said conduit resulting from water drops exiting and freezing at said conduit outlet end.

3. The combination of the refrigerator cabinet including an outer shell surrounding and spaced from an inner liner, said liner forming a sealed freezer compartment within said cabinet and having an access opening, a refrigeration system for cooling said freezer compartment to a temperature below freezing, a door on said cabinet adapted to close the access opening of said freezer compartment, an automatic ice maker cooling a water freezing tray in said freezing compartment, a water supply conduit having its outlet end positioned above said tray, said conduit comprising a relatively long substantially horizontal intermediate linear portion formed with smooth downwardly curved forward and rear portions respectively, at each end thereof, said conduit intermediate portion having a flattened upper surface in intimate thermal engagement with the refrigerator top wall outer shell, said intermediate portion having a composite cross section whereby the upper one-half forms a semi-square section and the lower half forms one-half of a cylinder section, said intermediate portion having a reduced tube positioned about midway between said front and rear downwardly curved portions, said reduced tube being concentrically aligned with the lower cylindrical portion of said conduit intermediate portion and having a radius of about one-half thereof, said reduced tube having frustoconical sections on both its upstream and downstream ends forming transition sections with said conduit intermediate portion, whereby upon said conduit supplying a predetermined quantity of water to the said tray the control valve means is closed shutting off the flow of water to said conduit whereby the meniscus of the water remaining in said conduit is positioned adjacent the downstream end of said reduced tube to obviate blockage of said conduit resulting from the build-up of frozen water drops at said conduit outlet end. 

1. A supply conduit for positioning between the inner liner and the outer shell of a refrigerator cabinet insulated top wall for supplying water to a freezing tray of an automatic ice maker, said conduit comprising; an intermediate linear portion formed with downwardly extending inlet and outlet portions, respectively, at each end thereof; said linear portion having a flattened upper surface for positioning in juxtaposed relation with the refrigerator top wall outer shell, said conduit intermediate portion having a reduced cylindrical tubular portion interposed between upstream and downstream segments of said linear portion, said reduced tubular portion having frustoconical sections on both its upstream and downstream ends joining with said upstream and downstream linear segments, respectively; whereby upon said conduit supplying a predetermined charge of water to the tray the flow of water to said conduit is stopped and the meniscus of the water remaining in said conduit is retained adjacent the downstream end of said tubular portion obviating blockage of said supply conduit by preventing water drops from exiting and freezing at said conduit outlet portion.
 2. A supply conduit for positioning between the inner liner and outer shell of a refrigerator top wall for supplying water to a tray of an automatic ice maker comprising, an intermediate linear portion formed with smooth downwardly curved inlet and outlet portions respectively, at each end thereof; said conduit intermediate portion having a flattened upper surface so as to be in juxtaposed relation with the refrigerator top wall outer shell, said conduit intermediate portion having a composite cross section whereby the upper half thereof forms a semi-square and the lower half forms one-half of the cylinder, said conduit intermediate portion having a reduced cylindrical tube positioned about midway between said inlet and outLet downwardly curved portions, said reduced tube being concentrically aligned with said lower cylindrical portion and having a radius of about one half thereof, said tube having frusto-conical sections on both its upstream and downstream ends joining with said conduit intermediate portion, whereby upon said conduit supplying a predetermined charge of water to the tray the flow of water through said conduit is stopped and the meniscus of the water remaining in said conduit is retained adjacent the downstream end of said tube to obviate blockage of said conduit resulting from water drops exiting and freezing at said conduit outlet end.
 3. The combination of the refrigerator cabinet including an outer shell surrounding and spaced from an inner liner, said liner forming a sealed freezer compartment within said cabinet and having an access opening, a refrigeration system for cooling said freezer compartment to a temperature below freezing, a door on said cabinet adapted to close the access opening of said freezer compartment, an automatic ice maker cooling a water freezing tray in said freezing compartment, a water supply conduit having its outlet end positioned above said tray, said conduit comprising a relatively long substantially horizontal intermediate linear portion formed with smooth downwardly curved forward and rear portions respectively, at each end thereof, said conduit intermediate portion having a flattened upper surface in intimate thermal engagement with the refrigerator top wall outer shell, said intermediate portion having a composite cross section whereby the upper one-half forms a semi-square section and the lower half forms one-half of a cylinder section, said intermediate portion having a reduced tube positioned about midway between said front and rear downwardly curved portions, said reduced tube being concentrically aligned with the lower cylindrical portion of said conduit intermediate portion and having a radius of about one-half thereof, said reduced tube having frusto-conical sections on both its upstream and downstream ends forming transition sections with said conduit intermediate portion, whereby upon said conduit supplying a predetermined quantity of water to the said tray the control valve means is closed shutting off the flow of water to said conduit whereby the meniscus of the water remaining in said conduit is positioned adjacent the downstream end of said reduced tube to obviate blockage of said conduit resulting from the build-up of frozen water drops at said conduit outlet end. 